A theory , even if a very good and elegant one , will suffer from confirmation bias while Facts and Evidence from experiments and reality enable, not just to test and verify theories but modify , alter , upgrade and choose from competing theories .

Karl Popper endorsed “Falsifiability – empirically falsifiable creteria“ as an explicit and logical way of establishing if a theory is scientific or not. Thus for any hypothesis to have credence, it must be inherently disprovable before it can become accepted as a scientific hypothesis or theory.

Very often, theories are constructed by systematically collecting data and carefully analyzing the data for patterns. And even when facts do not play a dominant role in giving birth to a theory, facts play a crucial role in shaping the theory’s development – if deductions from a theory are incorrect, the theory will be changed or abandoned.

Ivory Tower Theoreticians and Conceptual Researchers , have in the past and and recently , have produced theories that were eventually proved wrong. For a very easy and common example , Aristotle postulated large cannonballs fell to earth faster than small ones, and this was repeated by many in different times and places until Galileo proved them wrong. Galileo was the first empiricist , one who performed original experiments not merely to destroy old theories but to provide the basis for new theories , further arguing and showing the way that empirical acquisition of knowledge was the only way to the truth.

A pure empiricist possessing “ strong empirical” relationship can make useful predictions, making the theory irrelevant.